test and measurement projects

This picture represents a whole family of “Test Stations” that incorporated a mechanical test fixture, a control system, instrumentation, and a PC to collect and display test data.

The picture above was for a small elastomer part. The Client's requirement was for the part to produce a certain force at specific amounts of deflections. To accomplish this, the fixture displaced the parts via numerical control and then through the use of strain gauges measured the resulting forces. The data was captured and saved in a database for future analysis.

Another example which falls into this same category of projects was to measure the deflection of show boards. Because of the potential damage to the instrumentation upon possible failure of the boards, a different approach was implemented. Instead of the classical stress/ strain approach, that equipment applied numerically controlled forces to the board and the displacement was then measured. That technique not only produced very nice results but was very tolerant of physical abuse and thus proved to be very reliable.

The software was designed to provide the flexibility to set up tests for individual parts or families. The number of test points and the specific pressure for each could be designated. The equipment also had the ability to pre-flex the boards before the actual measurements were acquired.

Another test station inspected “drum maintenance drawers” for a printer. The physical dimensions were verified when test parts was placed into the test station. This ensured that the parts would properly fit into printers in the field.

A number of actuation were exercised and electrical measurements were taken to ensure that the drawer assembly functioned properly. The most critical measurement was to evaluate a critical surface profile. The profile was measured by “sweeping” a LVDT across the surface with a stepping motor. The “Y” measurements was then plotted across the “X” axis. Once the data was captured, 12 analytical tests were performed by the software to determine that all good parts passed and all bad parts failed.

That was a very successful test station. Once the data was captured and stored, it was very easy to be “exported” into an Excel format for easy analysis.